Substrate Storage Container And Positioning Method Of The Same

ABSTRACT

To provide a substrate storage container which, even when the substrate storage container is mounted on a machine with the container body&#39;s door element side inclined downward, can be suitably positioned without causing any hindrance to later operation, as well as providing a positioning method of the same, a container body  1  for accommodating a multiple number of precision substrates in alignment, a door element for opening and closing the open front of container body  1  and a multiple number of positioning parts  40  arranged on the bottom of container body  1  are provided. Each positioning part  40  is formed as a concave portion with a pair of parallel ribs  2  formed on the bottom surface of container body  1  and inner surfaces  9  of curved portions  8  of a track  6  formed in a bottom plate  4.  Inner surfaces  9  of track  6  are formed to be inclined linearly becoming gradually wider downwards from their top while the upper ends of inner surfaces  9  are extended to an opposing area  2   a  located between the lower ends of paired parallel ribs  2.

TECHNICAL FIELD

The present invention relates to a substrate storage container for usein storage, shipment, transportation, preservation of substrates such assemiconductor wafers etc., as well as relating to a positioning methodof the same.

BACKGROUND ART

In recent years, development of semiconductor parts into increasinglyfine structures and the development of interconnections into smallerpitches have proceeded. In view of this, a substrate storage container,having a high sealability that provides prevention against contaminationof the precision substrates, such as semiconductor wafers, held therein,and having a capability of being handled automatically, is demanded. Inorder to deal with such industry needs, there have been substratestorage containers whose door element for opening and closing thecontainer body is automatically attached to, and removed from, thecontainer body (see patent documents 1 and 2).

A substrate storage container of this type includes: for example, asshown in FIGS. 10 to 12, a container body 1 for accommodating a multiplenumber of unillustrated precision substrates; a multiple number ofpositioning parts 40A arranged at the bottom of this container body 1; adoor element 20 for opening and closing the open front of container body1; and a locking mechanism for locking and unlocking door element 20fitted to the front of container body 1, and can be positioned andmounted on unillustrated processing equipment by means of the multiplepositioning parts 40A.

Container body 1 has a robotic flange that is held by an automatictransporter called an OHT, attached on the top thereof, and is hoistedand conveyed with the robotic flange being held thereby. Multiplepositioning parts 40A are arranged at the bottom of container body 1 ina predetermined pattern. Each positioning part 40A is composed of a pairof parallel ribs 2 formed on the bottom surface of container body 1 anda hollow track 6A formed in a bottom plate 4 covering the bottom surfaceof container body 1 and fitted around the paired parallel ribs 2 frombelow.

The locking mechanism, though not illustrated, is incorporated in thedoor element and locked or unlocked by an actuation key of a doorelement opening/closing device as a part of the processing equipment.The processing equipment has a multiple number of positioning pins 50that will fit into positioning elements 40A, set (see FIG. 12) on themounting surface on which a substrate storage container is mounted, andalso has a sensor for detecting the presence of a substrate storagecontainer.

Patent Document 1:

Japanese Patent Application Laid-open 2000-58633

Patent document 2:

Japanese Patent Application Laid-open 2003-174081.

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

Since the conventional substrate storage container is constructed asdescribed above it has its center of gravity off the center of containerbody 1 to the front side because it has the heavy locking mechanismincorporated in the door element, hence the front side tends to beinclined downwards. This phenomenon occurs more frequently when a lowernumber of precision substrates are stored than when the maximum numbersubstrates are fully stored therein. If the substrate storage containeris positioned and mounted to the processing equipment while its frontside remains inclined downwards the substrate storage container isunlikely to slide due to frictional resistance arising when positioningpins 50 of the processing equipment come into contact with positioningparts 40A, hence becomes stuck midway resulting in the serious problemthat the container cannot be positioned with high precision.

Further since the substrate storage container is hoisted at its roboticflange, it cannot be said hat it is easy to support the substratestorage container in a stable condition. Hence there is a fear thatpositioning parts 40A of container body 1 cannot be put into uniformcontact with and fitted to respective positioning pins 50 of theprocessing equipment. As a result, there occurs the problem that thesubstrate storage container stops in a displaced and inclined positionon the processing equipment, or causes sensor detection failures,resulting in an interruption of later operation.

The present invention has been devised in view of the above, it istherefore an object of the present invention to provide a substratestorage container which, even when the substrate storage container ismounted on a machine with the container body's door element sideinclined downward, can be suitably positioned without causing anyhindrance to later operation, as well as providing a positioning methodof the same.

Means for Solving the Problems

In order to solve the above problem, a substrate storage container ofthe present invention comprises: a container body for accommodatingsubstrates; a door element for opening and closing the open front of thecontainer body; and a plurality of positioning parts provided on thebottom of the container body, and is characterized in that eachpositioning part includes a plurality of long pieces disposed apartfrom, and opposing, each other, and a plurality of short pieces locatedat least at lower positions between the ends of the multiple longpieces, and among the plurality of long and short pieces, at least theinner surfaces of the individual short pieces are formed to be inclinedgradually becoming wider from the bottom portion of the container bodydownwards while the upper part of the interior surfaces are extended tothe area between the plural long pieces.

Here, the bottom of the container body may be constructed of the bottomsurface of the container body and a plate attached to the bottom surfaceof the container body; plural pairs of parallel ribs may be provided onthe bottom surface of container body, each pair of ribs disposed apartfrom, and opposing, each other, so as to serve as the plural long piecesof the positioning part; and a plurality of hollow tracks enclosingindividual pairs of parallel ribs arranged with the curved portions ofeach track may be made to serve as the plural short pieces of thepositioning part.

Further, a locking mechanism incorporated in the door element forlocking the door element that covers the front of the container body maybe provided and the locking mechanism can be constructed of: arotational body which is supported on the door element and rotated byexternal actuation; a plurality of advancing/retractable pieces whichmove inwards and outwards of the door element in accordance with therotation of the rotational body; and engaging parts provided forindividual advancing/retractable pieces, caused to project from, andretracted into, the periphery of the door element and be inserted intoconcave portions in the inner periphery at the front of the containerbody, in accordance with the advancing and retracting movement of theadvancing/retractable pieces.

Moreover, the plate of the container body may be formed using at leastone kind of thermoplastic resin selected from a group of polycarbonate,polybutylene terephthalate, polyether etherketone, polyether imide,polyether sulfone, polyacetal and liquid crystal polymer, which contain,at least, one kind of additive selected from a group of carbon fibers,glass fibers, carbon powder, fullerene, carbon nanotube, syntheticfibers, metallic fibers, fluoro resin, silicone, talc and mica.

Furthermore, each positioning part may be constructed so that the plurallong pieces are divided into parts with respect to the longitudinaldirection and may include a sectioning block which becomes thinner fromthe bottom of the container body downwards.

Also the sectioning block of each positioning part may be formed in ahollow conical shape.

Additionally, in order to solve the above problem, the present inventionis a substrate storage container which is mounted on a plurality ofpositioning pins of processing equipment by means of a plurality ofpositioning parts, and is characterized in that in each positioning parta pair of inner sides opposing each other are formed each in thelengthwise direction and in the widthwise direction, and when thepositioning parts are fitted onto the plural positioning pins of theprocessing equipment, at least, three inner sides of the four innersides of each positioning part are brought into contact with thepositioning pin.

Here, the paired inner sides opposing each other in the lengthwisedirection of each positioning part may be formed by the inner surfacesof a paired of parallel ribs.

Still more, in order to solve the above problem, the present inventionis a positioning method of a substrate storage container which ismounted on a plurality of positioning pins of processing equipment bymeans of a plurality of positioning parts and is characterized in thatin each positioning part a pair of inner sides opposing each other areformed each in the lengthwise direction and in the widthwise direction,and when the positioning parts are fitted onto the plural positioningpins of the processing equipment, at least, three inner sides of thefour inner sides of each positioning part are brought into contact withthe positioning pin.

Here, the substrate defined in the scope of the claims may be variouskinds of precision substrates. Specific examples include semiconductorwafers having a diameter of 300 mm, 400 mm and 450 mm, glass masks,liquid crystal glass, storage disks and the like. The container body maybe either a front open box called FOUP, or a front open box called FOSB.The container body may be either, transparent, translucent or opaque andcan be formed with a see-through window at the backside wall, side wall,ceiling or the like, as appropriate. The door element may be constructedof either a single plate or a plurality of plates and may be eithertransparent, translucent or opaque.

The door element is provided with a locking mechanism. This lockingmechanism may be constructed of a rotational body which is supported onthe door element and rotated by an actuation outside the door element, aplurality of advancing/retractable bars which are slidably supported bythe door element and coupled rotatably to the rotational body and movein and out along the direction from the interior to the exterior of thedoor element in accordance with the rotation of the rotational body, andengaging rollers which are supported rotatably near the holes in theperiphery of the door element and coupled rotatably to the distal endsof the individual advancing/retractable bars, and come in and out fromthe holes in the periphery of the door element in accordance with theadvancing/retracting movement of the advancing/retractable bars.

Alternatively, the locking mechanism maybe constructed of a rotationalbody which is supported on the door element and rotated by an actuationoutside the door element, a plurality of advancing/retractable shaftswhich are slidably supported on the door element by means of bearingsand coupled rotatably in a direct or indirect manner with the rotationalbody and move in and out along the direction from the interior to theexterior of the door element in accordance with the rotation of therotational body, and rollers which are supported rotatably on theadvancing/retractable shafts and come in and out from the holes in theperiphery of the door element in accordance with theadvancing/retracting movement of the advancing/retractable shafts. Whenthe rotational body and advancing/retractable shafts are coupled in anindirect manner, it is possible to couple the rotational body withadvancing/retractable shafts, by use of crank engagement or the like.

Under conditions so as to prevent generation of dust and dirt, it isalso possible to construct the locking mechanism of a gear which issupported on the door element and rotated by an actuation outside thedoor element, a plurality of advancing/retractable bars which areslidably supported by the door element and coupled to the gear by way ofa second gear and move in and out along the direction from the interiorto the exterior of the door element in accordance with the rotation ofthe gear, and engaging claws which are formed at the distal ends of theindividual advancing/retractable bars and come in and out from the holesin the periphery of the door element in accordance with theadvancing/retracting movement of the advancing/retractable bars, wherebyit is possible to rotatably support the ends of advancing/retractablebars on a position off the center of the second gear.

The bottom of the container body is mainly constituted by the bottomsurface of the container body and the plate attached to the bottomsurface of the container body, but may be formed of either the bottomsurface of the container body alone, or a plate attached to thecontainer body alone. The plate may be either greater or smaller thanthe bottom surface of the container body, and its shape may be modifiedinto a rectangle, polygon, approximately U-shape, Y-shape, etc.

The multiple long pieces constituting each positioning part may beopposing walls of a block having an approximately M-shaped section, ormay be opposing long walls of a block having an approximatelyrectangular shape, viewed in plan. These multiple long pieces may or maynot be formed so as to be inclined becoming wider as they go downwardsfrom the bottom of the container body.

Other than the above, each positioning part may be constructed of a pairof parallel ribs provided on the bottom surface of the container bodyand a hollow track provided in the bottom surface of the container bodyand enclosing the paired parallel ribs while the track's curved portionsmay be positioned from below between the paired parallel ribs.Alternatively, each positioning part may be constructed of a pair ofparallel ribs provided on a plate and a hollow track provided in theplate and enclosing the paired parallel ribs while the track's curvedportions may be extended from below between the paired parallel ribs.

Concerning the hollow track, it is formed in an approximately ovalshape, when viewed in plan, and is composed of an annular peripheralwall enclosing the paired parallel ribs and inclined surfaces formed inthe inner surface of the peripheral wall, forming a hollow at the centerof the area enclosed by the peripheral wall. In this case, a pair ofparallel ribs is divided into front and rear paired parallel ribs, andthese front and rear paired parallel ribs are enclosed by respectivetracks while a sectioning block is interposed between the paired tracks.Further, the sectioning block is preferably formed in a conical shape,approximately ellipsoid or frustoconical shape.

EFFECTS OF THE INVENTION

The present invention provides an effect that it is possible to suitablyposition a substrate storage container even when the substrate storagecontainer is mounted on a machine with the container body's door elementside inclined downward. Further, it is possible to effectively preventoccurrence of hindrance to the operation after positioning.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic overall perspective view showing an embodiment of asubstrate storage container according to the present invention.

FIG. 2 is a bottom view showing an embodiment of a substrate storagecontainer and its positioning method according to the present invention.

FIG. 3 is a bottom view showing a positioning part in an embodiment of asubstrate storage container and its positioning method according to thepresent invention.

FIG. 4 is a sectional view cut along a line IV-IV in FIG. 3.

FIG. 5 is a bottom view showing the second embodiment of a substratestorage container and its positioning method according to the presentinvention.

FIG. 6 is a bottom view showing a positioning part in the secondembodiment of a substrate storage container and its positioning methodaccording to the present invention.

FIG. 7 is a sectional view cut along a line VII-VII in FIG. 6.

FIG. 8 is an illustrative view showing a measurement jig for bottomplates in an embodiment example of a substrate storage container and itspositioning method according to the present invention.

FIG. 9 is an illustrative view showing a state where a container body isplaced on a measurement jig for bottom plates in an embodiment exampleof a substrate storage container and its positioning method according tothe present invention.

FIG. 10 is a bottom view showing a conventional substrate storagecontainer.

FIG. 11 is a bottom view showing a positioning part of a conventionalsubstrate storage container.

FIG. 12 is a sectional view cut along a line XII-XII in FIG. 11.

DESCRIPTION OF REFERENCE NUMERALS

-   1 container body-   2 paired parallel ribs (long pieces, inner surfaces)-   2A front, paired parallel ribs-   2 a opposing area-   2B rear, paired parallel ribs-   3 reinforcing rib-   4 bottom plate (plate)-   6 track-   7 linear portion-   8 curved part (short piece)-   9 inner surface-   12 rim portion (open front)-   13 engagement hole (concave portion)-   20 door element-   21 fitting plate-   22 cover plate-   23 actuation passage-hole-   30 locking mechanism-   40 positioning part-   41 sectioning block-   42 outer peripheral surface-   50 positioning pin

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings, a preferred embodiment of the presentinvention will be described hereinbelow. A substrate storage containerof the present embodiment is also called a thin-plateaccommodation/preservation container or shipment container. As shown inFIGS. 1 to 4, the substrate storage container is comprised of acontainer body 1 for accommodating a plurality (e.g., 25 or 26 pieces)of precision substrates such as, for instance, 12-inch semiconductorwafers, a door element 20 removably fitted to open and close the openfront of the container body 1, a pair of left and right lockingmechanisms 30 for locking and unlocking door element 20 that fits andencloses the front of container body 1, by external operation from adoor element opening and closing device of processing equipment, and aplurality of positioning parts 40 arranged in the bottom of containerbody 1.

As shown in FIG. 1, container body 1 is formed of a predetermined resininto a transparent front-open box type in which both side walls arepartially inclined inwards at their rear part so that the area of thebackside wall is smaller than the area of the laterally long front, andprovides the functions of accommodating a multiple number of thin, roundprecision substrates (not shown) in alignment, from top to bottom.

Though not illustrated, on both sides in the interior of container body1 are provided integrally or removably with a pair of supporting platesof an approximately widely open-V-shape or approximately semicircularshape when viewed in plan. On the opposing surfaces of these paired leftand right supporting plates, teeth of an approximately widelyopen-V-shape or approximately semicircular-arc shape when viewed inplan, are formed integrally in parallel to each other and arrangedvertically with a predetermined pitch, so that a pair of left and rightteeth support one precision substrate approximately horizontally.

Though not illustrated, each tooth is comprised of a flat plate formedin an approximately widely open-V-shape or an approximatelysemi-circular arc shape when viewed in plan, so as to go along theperiphery of the precision substrate, a front medium-thick area formedin the curved front and interior part of the flat plate, a flat frontthick area formed on the front outer side of the flat plate and outsidethe front medium-thick area, or in other words, located close to thesupporting plate, a rear medium-thick area formed in the rear part ofthe flat plate, and a rear thick area formed on the rear outer part ofthe flat plate and in front of the rear medium-thick area and locatedclose to the supporting plate. A step that will come into contact withthe precision substrate is formed between the front medium-thick areaand the front thick area, so that the precision substrate is supportedapproximately horizontally between flat front medium-thick areas andrear medium-thick areas.

As shown in FIG. 2, a pair of parallel ribs 2 opposing each other arearranged at each of the front sides and the rear center on the bottomsurface of container body 1 while a bottom plate 4 made of a thin plateis removably attached to the bottom surface of container body 1. Amultiple number of detachable identifiers 5 are fitted in the rear partof this bottom plate 4 and detected by processing equipment so that thesubstrate storage container type, the number of precision substrates,etc. can be known.

As shown in FIGS. 2 and 3, a bar-shaped reinforcement rib 3 isintegrally bridged between paired parallel ribs 2 at their approximatecenter, so as to form an approximately H-shape, as a whole, when viewedfrom the bottom. Each of paired parallel ribs 2 is provided in a smoothlinear plate-form without irregularity and is projected downward fromthe bottom surface of container body 1 (see FIG. 4).

Bottom plate 4 is formed in an approximately polygonal shape or thelike, when viewed in plan, corresponding to the size of the bottomsurface of container body 1, as shown in FIG. 2, and is bored with aplurality of (three in this embodiment) approximately oval-shapedpassage holes laid out forming a substantially Y-shaped pattern whenviewed from the bottom. Formed integrally with the periphery of eachpassage hole is a hollow track 6 that is fitted from below and enclosesthe lower part of paired parallel ribs 2.

As shown in FIGS. 3 and 4, each track 6 is formed of a pair of linearparts 7 opposing, and apart from, each other, overlapping parallel ribs2 from their outside and a pair of short, curved parts 8 integrallyformed between the ends of the paired linear parts 7 and opposing eachother, into an approximately oval shape when viewed from the bottom, andprojected toward the bottom surface of container body 1 (upwards) frombottom plate 4.

Each curved part 8 is formed so that its outer peripheral surface isapproximately semicircularly arced while a smooth inner surface 9without irregularity is formed to be narrower than the distance betweenpaired parallel ribs 2. This inner surface 9 is formed so as to begradually inclined linearly becoming wider downwards from bottom plate 4that is the bottom of container body 1 (see FIG. 4). This inner surface9 is inclined from the opposing area 2 a, located between the lower endsof paired parallel ribs 2 to the lower position between the ends ofpaired parallel ribs 2.

Processing equipment has three positioning pins 50, projected on themounting surface on which a substrate storage container is placed, andarranged in an approximately Y-shaped pattern when viewed in plan so asto fit into multiple tracks 6, and has a sensor for detecting thepresence of the substrate storage container. The distal end of eachpositioning pin 50 is formed with a curvature in an approximatelyelliptic spherical shape.

As shown in FIG. 1, on each side of the bottom surface of container body1, a guide rail 10 having an approximately L-shaped cross section,extended from the front to the rear is jutted out, so that these a pairof left and right guide rails 10 can provide convenience duringtransportation of the substrate storage container. A robotic flange 11having an approximately rectangular shape when viewed in plan, isintegrally or removably attached at the center of the top of containerbody 1. This robotic flange 11 is lifted by an automatic transportercalled an OHT so as to convey the substrate storage container betweenprocessing steps.

A rim portion 12 having an approximately fallen-L-shaped section isformed around the periphery of the open front of container body 1 sothat it extends outwards. A multiple number of recesses are formed attop and bottom on the inner peripheral surface of this rim portion 12,as engagement holes 13 for locking the rectangular-shaped door element20. Thick disk-shaped or fallen U-shaped carriage handles are optionallyattached to both side walls of container body 1, so that the substratestorage container can be transported by holding these carriage handles.

Container body 1, supporting plates, teeth, bottom plate 4, guide rails10, robotic flange 11 and carriage handles are formed of, for example,polycarbonate, polyether imide, polyether etherketone, cyclo-olefinresin or the like. A conductivity imparting agent etc. may be added asappropriate to these materials.

As shown in FIG. 1, door element 20 is composed of a fitting plate 21having an approximately dish-like section, to be detachably fitted intorim portion 12 of container body 1 and a cover plate 22 that covers theopening front of fitting plate 21, and holds precision substrates by itselastic front retainer (not shown) in cooperation with a rear retainer(not shown) arranged on the interior rearside of container body 1.

Fitting plate 21 is formed in a laterally-long, approximatelyrectangular shape with its four corners rounded when viewed from thefront, and has a peripheral wall having an approximately L-shaped orapproximately H-shaped or approximately Z-shaped section for improvedrigidity. An endless seal gasket fitted to this peripheral wall deformsand fits into rim portion 12 of container body 1 to assure sealing.

This seal gasket, though not illustrated, is formed of, for example, ahollow frame-shaped base, a tapering, flexed piece that is obliquelyprojected from the base, extending along the periphery on the outer sideof the base and a single or a multiple number of fitting ribs which areprojected from the base and forcibly fitted and compressed into afitting holding groove formed on the peripheral wall of fitting plate21, and provides a one-way sealing function which, when a pressuredifference occurs between the exterior and interior of the substratestorage container sealed by door element 20, prevents air containingdust and dirt from flowing from the exterior into the interior of thesubstrate storage container, and permits air to flow out from theinterior to the exterior of the substrate storage container.

A seal gasket of this kind may be formed of, for example siliconerubber, fluoro rubber, thermoplastic polyester elastomer, thermoplasticpolyolefin elastomer etc., so as to be elastically deformable.

A multiple number of water drain holes to be used during washing areformed at predetermined intervals on the peripheral wall of fittingplate 21 while a pair of left and right holes are formed a predetermineddistance apart at the top and bottom of the peripheral wall so that eachhole opposes engagement hole 13 of container body 1 when door element 20is fitted. A multiple number of holes for attachment of cover plate 22are formed at predetermined intervals in the peripheral wall on bothleft and right sides of fitting plate 21.

As shown in FIG. 1, cover plate 22 is provided in a plate-like form, anda pair of actuation passage-holes 23 for locking mechanisms 30 of arectangular shape when viewed from the front, are formed on both leftand right sides around the center of the plate, an actuation key of thedoor opening and closing device of processing equipment being insertedinto each actuation passage-hole 23.

Here, door element 20 may be formed of, for example, polycarbonate,fluorine-containing polycarbonate, polybutylene terephthalate, polyetheretherketone, polyether imide, polyacetal or the like.

Though not detailed herein, each locking mechanism 30 includes: a rotaryreel as a rotational body which is fitted and supported on a cylindricalrib inside fitting plate 21 and rotated by rotational actuation of anactuation key from without; a plurality of advancing/retractable barswhich are slidably supported between cams of fitting plate 21 and coverplate 22 and linearly slide in and out of door element 20 in accordancewith the rotation of the rotary reel; and engaging claws as engagingportions which are arranged at the distal ends of individualadvancing/retractable bars, come in and out from the holes in theperipheral wall of the door element periphery to fit into and engageengagement holes 13 in rim portion 12, in accordance with the advancingand retracting movement of the advancing retractable bars.

Additionally, the coupling position and dimensions of the door elementopening and closing device are specified for every container size by theSEMI standards. For example, the specifications of the device interfacefor automatically opening and closing door element 20 of a processingcontainer for storing 12 inch (300 mm) semiconductor wafers inalignment, corresponds to the door element opening and closing devicedefined by SEMI standard E62.

Locking mechanism 30 is formed of, for example, polycarbonate,fluorine-containing polycarbonate, polybutylene terephthalate,polybutylene terephthalate, polyether etherketone, polyether imide,polyacetal or the like.

Each positioning part 40 is formed of, as shown in FIGS. 3 and 4, aconcave portion constructed by a pair of parallel ribs 2 formed on thebottom surface of container body 1 and a pair of curved parts 8 in track6 formed in bottom plate 4, parallel rib 2 being longer than curved part8. The inner surfaces 9 of curved parts 8 in the widthwise direction oftrack 6 are formed to be inclined linearly becoming gradually wider fromthe top to bottom with the upper ends extended up to the opposing area 2a where the lower ends of paired parallel ribs 2 oppose each other.

In accordance with the above configuration, when the substrate storagecontainer is positioned with respect to processing equipment with itsheavier front side inclined downwards, positioning pin 50 comes intocontact with, at least, three sides of the four sides, i.e., the innersurfaces of paired parallel ribs 2 and paired inner surfaces 9 of track6, which constitute each positioning part 40. Accordingly, it ispossible to correctly slide the substrate storage container into placewithout any wobble. Thus, it is possible to expect high precisionpositioning, and the substrate storage container will not slip out ofplace if the container is affected by some vibrations or the like.

Since it is also possible to bring positioning parts 40 into uniformcontact with respective multiple number of positioning pins 50 ofprocessing equipment, there will not occur any event such as thesubstrate storage container stopping on the processing equipment in adisplaced and inclined position. Accordingly, there no longer occur anysensor detection failures due to stopping of the substrate storagecontainer in a displaced and inclined position, hence it is possible toprevent interruption of later operation.

Further, the upper ends of track 6's smooth inner surfaces 9 withoutirregularity are extended up to the opposing area 2 a where the lowerends of paired parallel ribs 2 oppose each other, so that the innersurfaces of paired parallel ribs 2 and inner surfaces 9 of track 6become approximately continuous. As a result, wobbling of the substratestorage container is minimized when positioned and can be placed at acorrect position without displacement.

As described above, when the substrate storage container having amultiple number of positioning parts 40 is positioned to the processingequipment having a multiple number of positioning pins 50, at leastthree side of the four sides of each positioning part 40 can be put intocontact with positioning pin 50, hence it is possible to achievepositioning of the substrate storage container with high dimensionalprecision.

Next, FIGS. 5 to-7 show the second embodiment of the present invention.In this case, a pair of parallel ribs 2 is divided into front pairedparallel ribs 2A and rear paired parallel ribs 2B, and these frontpaired parallel ribs 2A and rear paired parallel ribs 2B are enclosed byrespective tracks 6 while a sectioning block 41 that separates the frontpaired parallel ribs 2A and the rear paired parallel ribs 2B into twoparts in the front-to-rear longitudinal direction is interposed betweena pair of tracks 6.

As shown in FIG. 7, sectioning block 41 is formed in a hollow conicalshape that gradually tapers downwards from bottom plate 4 with its outerperipheral surface 42 formed smoothly without irregularity, wherebypositioning pin 50 comes into sliding contact with this outer peripheralsurface 42 to be guided into the predetermined position. Othercomponents are the same as the above embodiment so the description isomitted.

Also in this embodiment, the same operation and effect as in the aboveembodiment can be expected. In addition, since sectioning block 41 thatguides positioning pin 50 is located between front paired parallel ribs2A and rear paired parallel ribs 2B and positioning pin 50 is put intocontact with the four sides, i.e., the inner sides of one pairedparallel ribs 2, inner surface 9 of track 6 and outer peripheral surface42 of sectioning block 41, the range in which positioning pin 50 iswobbled can be made smaller. Accordingly, it is obvious thathigh-precision positioning can be expected and that it is possible toprevent the substrate storage container from being displaced from thecorrect position by vibrations and the like.

Though in the above embodiment, description was made on a front open boxtype container body 1 that opens in the horizontal direction only, thecontainer body 1 may be placed upwards when door element 20 is removedor precision substrates are put in and taken out. It is also possible toprovide a supporting frame instead of supporting plates. In thissupporting frame a multiple number of teeth may be provided parallel toeach other and arranged in the vertical direction on vertical ribs.Further, it is also possible to provide retaining grooves having anapproximately fallen U-shaped or approximately fallen V-shaped section,disposed between adjacent teeth, in the rear of the supporting frame, sothat the peripheral edges at both sides in the rear of the precisionsubstrates can be supported by the retaining grooves.

Here, each tooth may be comprised of a flat plate formed in anapproximately widely open-V-shape, when viewed in plan so as to go alongthe periphery of the precision substrate, a front medium-thick ribformed in the bent, front inner area on the flat plate, a front thickarea formed on the front outer side of the flat plate and outside thefront medium-thick rib, or in other words, located close to thesupporting frame, a rear medium-thick area formed in the rear part ofthe flat plate, wherein a step is formed between the front medium-thickrib and the front thick area, so that the precision substrate issupported approximately horizontally between approximately flat, frontmedium-thick ribs and rear medium-thick areas.

Instead of the bottom surface of container body 1, a multiple number ofpositioning parts 40 maybe formed on bottom plate 4. Further, bottomplate 4 may be extended so as to form raised opposing walls on bothsides thereof, which oppose the side walls of container body 1 andcarriage handles for holding may be attached to the opposing walls.Also, a raised wall that is located on the backside of container body 1may be provided in the rear of bottom plate 4 so that ID codes, IC tagsetc., may be applied to, fitted to, supported by, this wall.

Also, when the peripheral part of the open front of container body 1 maybe formed so as to have an approximately fallen L-shaped section and itsdistal end portion may be formed so as to have an approximately U-shapedsection, it is possible to use these depressed interior spaces asengagement holes 13. Further, a first endless seal gasket is attached tothe peripheral part on the rear side of fitting plate 21 while a secondendless seal gasket is attached around the peripheral wall of fittingplate 21 so that the second seal gasket can be positioned on the outerside of the first seal gasket with respect to its width direction.

Further, concerning bottom plate 4 and positioning part 40, it ispossible to form them using at least one kind of thermoplastic resinselected from a group of polycarbonate, polybutylene terephthalate,polyether etherketone, polyether imide, polyether sulfone, polyacetaland liquid crystal polymer, which contain, at least, one kind ofadditive selected from a group of carbon fibers, glass fibers, carbonpowder, fullerene, carbon nanotube, synthetic fibers, metallic fibers,fluoro resin, silicone, talc and mica, in an appropriate amount.Moreover, positioning part 40 may be formed integrally with containerbody 1 or may be integrated by insert molding etc., after it has beenformed of a material different from that of container body 1.

EMBODIMENT EXAMPLE

Next, embodiment examples of the substrate storage container accordingto the present invention and its positioning method will be describedand compared with a comparative example.

Embodiment Example 1

First, as shown in FIG. 8, using a measurement jig for bottom plates,produced with the dimensions based on the SEMI standard, an emptysubstrate storage container provided with the positioning partsillustrated in the first embodiment was set on this measurement jig, andafter the container was moved from the normal position to the positionshown in FIG. 9, the container was released from the hand so as to checkwhether it would go back to the original position. Ten samples weretested, and the result is shown in Table 1.

Embodiment Example 2

An empty substrate storage container provided with the positioning partsillustrated in the second embodiment was set on the above measurementjig, and after the container was moved from the normal position to theposition shown in FIG. 9, the container was released from the hand so asto check whether it would go back to the original position. Ten sampleswere tested, and the result is shown in Table 1.

Comparative Example

An empty substrate storage container provided with the conventionalpositioning parts shown from FIGS. 10 to 12 was set on the abovemeasurement jig, and after the container was moved from the normalposition to the position shown in FIG. 9, the container was releasedfrom the hand so as to check whether it would go back to the originalposition. Ten samples were tested, and the result is shown in Table 1.TABLE 1 Test for checking whether the positioning parts went up on thepositioning pin Whether the positioning parts went up on the positioningpins Embodiment example 1 None (0/10) Embodiment example 2 None (0/10)Comparative example occurred (9/10)

1. A substrate storage container comprising: a container body foraccommodating substrates; a door element for opening and closing theopen front of the container body; and a plurality of positioning partsprovided on the bottom of the container body, characterized in that eachpositioning part includes a plurality of long pieces disposed apartfrom, and opposing, each other, and a plurality of short pieces locatedat least at lower positions between the ends of the multiple longpieces, and among the plurality of long and short pieces, at least theinner surfaces of the individual short pieces are formed to be inclinedgradually becoming wider from the bottom portion of the container bodydownwards while the upper part of the interior surfaces are extended tothe area between the plural long pieces.
 2. The substrate storagecontainer according to claim 1, wherein the bottom of the container bodyis constructed of the bottom surface of the container body and a plateattached to the bottom surface of the container body; plural pairs ofparallel ribs are provided on the bottom surface of container body, eachpair of ribs disposed apart from, and opposing, each other, so as toserve as the plural long pieces of the positioning part; and a pluralityof hollow tracks enclosing individual pairs of parallel ribs arrangedwith the curved portions of each track are made to serve as the pluralshort pieces of the positioning part.
 3. The substrate storage containeraccording to claim 1, further comprising: a locking mechanismincorporated in the door element for locking the door element thatcovers the front of the container body, wherein the locking mechanismincludes: a rotational body which is supported on the door element androtated by external actuation; a plurality of advancing/retractablepieces which move inwards and outwards of the door element in accordancewith the rotation of the rotational body; and engaging parts providedfor individual advancing/retractable pieces, caused to project from, andretracted into, the periphery of the door element and be inserted intoconcave portions in the inner periphery at the front of the containerbody, in accordance with the advancing and retracting movement of theadvancing/retractable pieces.
 4. The substrate storage containeraccording to claim 2, wherein the plate of the container body is formedusing at least one kind of thermoplastic resin selected from a group ofpolycarbonate, polybutylene terephthalate, polyether etherketone,polyether imide, polyether sulfone, polyacetal and liquid crystalpolymer, which contain, at least, one kind of additive selected from agroup of carbon fibers, glass fibers, carbon powder, fullerene, carbonnanotube, synthetic fibers, metallic fibers, fluoro resin, silicone,talc and mica.
 5. The substrate storage container according to claim 2,wherein each positioning part is constructed so that the plural longpieces are divided into parts with respect to the longitudinal directionand includes a sectioning block which becomes thinner from the bottom ofthe container body downwards.
 6. The substrate storage containeraccording to claim 5, wherein the sectioning block of each positioningpart is formed in a hollow conical shape.
 7. A substrate storagecontainer which is mounted on a plurality of positioning pins ofprocessing equipment by means of a plurality of positioning parts,characterized in that in each positioning part a pair of inner sidesopposing each other are formed each in the lengthwise direction and inthe widthwise direction, and when the positioning parts are fitted ontothe plural positioning pins of the processing equipment, at least, threeinner sides of the four inner sides of each positioning part are broughtinto contact with the positioning pin.
 8. The substrate storagecontainer according to claim 7, wherein the paired inner sides opposingeach other in the lengthwise direction of each positioning part areformed by the inner surfaces of a paired of parallel ribs.
 9. Apositioning method of a substrate storage container which is mounted ona plurality of positioning pins of processing equipment by means of aplurality of positioning parts, characterized in that in eachpositioning part a pair of inner sides opposing each other are formedeach in the lengthwise direction and in the widthwise direction, andwhen the positioning parts are fitted onto the plural positioning pinsof the processing equipment, at least, three inner sides of the fourinner sides of each positioning part are brought into contact with thepositioning pin.